Sriramulu Vinnakota

Inelastic analysis of partially restrained unbraced steel frames

The development of a finite element for use in the inelastic ultimate load analysis of steel frames is presented. The element is capable of modelling partial plastification within the cross-section, residual stresses, shift in the elastic neutral axis with plastification and partially restrained connections. The incremental equations of equilibrium are written and the constant work implementation of the simple Euler stepping algorithm is used to trace the full nonlinear load-deformation response of several structural steel frames with partially restrained connections. The effect of connection stiffness on the load-deflection behaviour and spread of plastification throughout the frames is quantified and discussed.

Toward design office moment-rotation curves for end-plate beam-to-column connections

Abstract A semi-analytic method to model moment-rotation curves for unstiffened extended end plate connections is presented. Two physically based parameters; connection initial stiffness and connection moment capacity, and one experimentally based parameter are used in a three-parameter power model. Good correlation between the proposed model and experimental results is shown. The proposed method is then simplified, resulting in moment-rotation curve modeling suitable for design office environments.

Parallel processing in the elastic nonlinear analysis of high-rise frameworks

Abstract The method of substructuring and the parallel processing technique of multitasking are applied in the analysis of high-rise structural frameworks. The performance of the proposed method is measured in both wall-clock time and connect time when run in a batch environment on a Cray Y-MP C90 supercomputer. An attempt is made to quantify the optimum number of processors that should be used in the analysis of rectangular frameworks based on the partitioning algorithm employed. Several high-rise planar structures are analyzed and the load-deformation response when subject to proportional and nonproportional loads is given.